Virtual Gluino Correction to the Decay Z → bb

We computed the O(α_s) virtual gluino correction to the process Z → bb in the minimal supersymmetric standard model, and investigated the dependence of the process on gluino and squark masses. For some values of masses, the correction implies about 7%-12% additional decrease of the ratio Γ(Z → bb)/ Γ (Z → hadrons) relative to the standard model expectation.